Just after ending his tour of Mexico this week, Pope Francis made comments today that could play a role in the U.S. presidential race. The Pope said that he thinks Trump “is not a Christian” because of the real estate mogul’s plan to build a wall along the U.S.-Mexico border.

The comment was reported by the Associated Press and came during Francis’ midair press conference with journalists on his way back to Rome.

“A person who thinks only about building walls, wherever they may be, and not building bridges, is not Christian,” the Pope said, reports The New York Times.

Trump quickly responded to the Pope’s remarks on his site:

“If and when the Vatican is attacked by ISIS, which as everyone knows is ISIS’s ultimate trophy, I can promise you that the Pope would have only wished and prayed that Donald Trump would have been President because this would not have happened. ISIS would have been eradicated unlike what is happening now with our all talk, no action politicians.

“The Mexican government and its leadership has made many disparaging remarks about me to the Pope, because they want to continue to rip off the United States, both on trade and at the border, and they understand I am totally wise to them. The Pope only heard one side of the story - he didn’t see the crime, the drug trafficking and the negative economic impact the current policies have on the United States. He doesn’t see how Mexican leadership is outsmarting President Obama and our leadership in every aspect of negotiation.

“For a religious leader to question a person’s faith is disgraceful. I am proud to be a Christian and as President I will not allow Christianity to be consistently attacked and weakened, unlike what is happening now, with our current President. No leader, especially a religious leader, should have the right to question another man’s religion or faith. They are using the Pope as a pawn and they should be ashamed of themselves for doing so, especially when so many lives are involved and when illegal immigration is so rampant.”

As USA Today notes, Trump did slam the Pope’s visit to the border earlier this week. He said that he doesn’t think the Pope “understands the danger of the open border we have with Mexico.”

“And I think Mexico got him to do it because Mexico wants to keep the border just the way it is because they’re making a fortune and we’re losing,” Trump added in a Fox Business Network interview before Francis’ visit.

Trump has repeatedly called for a “beautiful” wall along the border and insists that he can make Mexico pay for it.

Donald J. Trump responds to Pope Francis' remarks: "I'm a very good Christian...he's questioning my faith and I was very surprised to see it." abcn.ws/1SUzhlX

Posted by ABC News on Thursday, Feb. 18, 2016